\begin{tikzpicture}
    \tkzDefPoints{0/0/A, 3/0/B}
    \tkzDefLine[mediator, normed](A,B)  \tkzGetPoints{m}{N}
    \tkzDefPointOnLine[pos=2.5](N,m)  \tkzGetPoint{M}
    \tkzInterLL(A,B)(M,N)  \tkzGetPoint{C}
    \tkzDefPointOnLine[pos=0.2](M,N)  \tkzGetPoint{P}
    \tkzDrawSegments(A,B  M,N)
    \tkzDrawSegments[dashed](A,P  B,P)
    \tkzMarkRightAngle(B,C,M)
    \tkzLabelPoints[right](M,N,P)
    \tkzLabelPoints[below](A,B)
    \tkzLabelPoints[below right](C)
\end{tikzpicture}

